On Mon, Oct 21, 2024 at 8:57 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > On Mon 21-10-24 08:41:00, Suren Baghdasaryan wrote: > > On Mon, Oct 21, 2024 at 8:34 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > > > On Mon 21-10-24 08:05:16, Suren Baghdasaryan wrote: > > > [...] > > > > Yeah, I thought about adding new values to "mem_profiling" but it's a > > > > bit complicated. Today it's a tristate: > > > > > > > > mem_profiling=0|1|never > > > > > > > > 0/1 means we disable/enable memory profiling by default but the user > > > > can enable it at runtime using a sysctl. This means that we enable > > > > page_ext at boot even when it's set to 0. > > > > "never" means we do not enable page_ext, memory profiling is disabled > > > > and sysctl to enable it will not be exposed. Used when a distribution > > > > has CONFIG_MEM_ALLOC_PROFILING=y but the user does not use it and does > > > > not want to waste memory on enabling page_ext. > > > > > > > > I can add another option like "pgflags" but then it also needs to > > > > specify whether we should enable or disable profiling by default > > > > (similar to 0|1 for page_ext mode). IOW we will need to encode also > > > > the default state we want. Something like this: > > > > > > > > mem_profiling=0|1|never|pgflags_on|pgflags_off > > > > > > > > Would this be acceptable? > > > > > > Isn't this overcomplicating it? Why cannot you simply go with > > > mem_profiling={0|never|1}[,$YOUR_OPTIONS] > > > > > > While $YOUR_OPTIONS could be compress,fallback,ponies and it would apply > > > or just be ignored if that is not applicable. > > > > Oh, you mean having 2 parts in the parameter with supported options being: > > > > mem_profiling=never > > mem_profiling=0 > > mem_profiling=1 > > mem_profiling=0,pgflags > > mem_profiling=1,pgflags > > > > Did I understand correctly? If so then yes, this should work. > > yes. I would just not call it pgflags because that just doesn't really > tell what the option is to anybody but kernel developers. You could also > have an option to override the default (disable profiling) failure strategy. Ok, how about "compressed" instead? Like this: mem_profiling=0,compressed > -- > Michal Hocko > SUSE Labs